Some kind of data analysis systems performs, when a processing request is received, analysis processing at the time the processing request is received. As an example of this type of data analysis system, there is a measured-data processing apparatus that measures an event that has occurred at an observation target and transfers the measured data to the next stage. The measured-data processing apparatus includes a data receiving unit, which receives event information indicating the type of event that has occurred and, after the measurement regarding the event information is started, generates time information that includes an absolute elapsed time until the event has occurred. The measured-data processing apparatus also includes an internal buffer that temporarily accumulates the event information and the time information. The measured-data processing apparatus also includes a data amount determination unit that determines the amount of data accumulated in the internal buffer. When the amount of data satisfies a first level, where the data amount is the lowest, and if the usage ratio for of the amount of data in the internal buffer exceeds a first rising time threshold value, the data amount determination unit determines that the amount of data has reached a second level where there is more data than the first level. When the amount of data satisfies to the second level and if the usage ratio is less than a first falling time threshold value, the data amount determination unit determines that the amount of data transmit has transmitted to the first level. The data amount determination unit further includes a data transfer unit. When it is determined that the data amount in the internal buffer is at the first level, the data transfer unit fetches the event information and the time information from the internal buffer, and transfers the fetched event information and the fetched time information to the next stage. When it is determined that the data amount in the internal buffer is at the second level, the data transfer unit fetches the event information and the time information from the internal buffer, and transfers the fetched event information and coarse time information obtained by degrading the precision level of the fetched time information to the next stage.
See, for example, Japanese Laid-Open Patent Publication No. 2010-128730.
In the measured-data processing apparatus described above, when the data arrival frequency is high, the amount of information is reduced by a certain amount and data are transferred at a period in which the data arrival frequency has decreased, so that the data transfer may be completed before the data arrival time.
However, since the number of accesses to data is not taken into account with the above measured-data processing apparatus, there is a problem with the efficiency of access to data stored in the storage device.